Re: Root Logins in X...

I'm just kidding, but I'm not sure how promoting good behavior is a
bad thing.

A few more ideas, off the top of my head:
A "Rescue Mode" in GDM which goes to a root session with minimal apps,
marked as "Rescue Mode", rather than a root X login (even though it does
need root credentials).
A prompt upon the first time a user tried to login to a normal X session
via GDM as root (separate from the "Rescue Mode"), warning them of the
risk they're taking, with a small checkbox that says something like
"never show me this warning again".